It is well known in the prior art to collect tissues, tissue samples and/or specimens, e.g. taken at a hospital which is then transferred to a laboratory or the like for histological examination. For a histological examination of human or animal tissues, the tissues are collected from the patients by the clinician in ambulatory environment (biopsies), or by surgeons during operation, then are placed in suitable carriers such as a container, typically filled with fixative such as formalin and sent to the histology laboratory for final examination.
As the tissue is received in the histology laboratory, the first operation performed by the histotechnicians are the accessioning and grossing.
The accessioning consists of a registration of the incoming tissues and insertion of the data in the laboratory information system (LIS). In this phase, a unique tissue code is assigned to the specimen. More specifically, tissues are received, sorted, labelled with barcoded labels (e.g., a barcode label on a carrier such as a container or cassette, in which the tissues are already received and/or in which the tissues will be placed) and related data are manually entered into a Laboratory Information System. The data includes, e.g., patient name, required examination and/or type of sample (e.g., organ name). Moreover, it is known that the recognition of number and size of the respective specimens is also done manually and the information is recorded via a voice recorder or hand-typed via a computer. These information must then be transferred into electronical data which is quite costly. Moreover, during further processing tissues can get lost out of the respective carrier, which cannot be determined or realized during processing, since no data about the respective tissue in the corresponding carrier is stored.
During the following grossing step, the tissue is removed from the carrier, e.g., a transportation container, and reduced in a way that is suitable for the next processes. The reduced tissue or specimen is placed inside a carrier. The reduced specimen must be small enough to be contained inside the carrier, which is, e.g., a standard histological cassette. It means that usually the tissue or specimen is about 0.5 to 5 mm thick, about 0.5 to 20 mm large and 0.5 to 40 mm long. Some tissues, such as small biopsies, are usually already small enough so that the reduction is not required. A polymer foam can be used inside the carrier if the tissue is small, to facilitate the positioning and to avoid an accidental loss of the tissue through the carrier, in particular, cassette slots. Several pieces of tissues of the same patient can be put together in the same carrier. After the preparation, the carrier is usually grouped together with several other carriers inside a rack or rack container. A rack may hold from few tens to few hundreds of carriers. The rack is then used to process several carriers together at the same time inside a tissue processor. The group of several carriers inside a rack is usually named “batch”. Even though the rack might be somehow identifiable via a corresponding code, there is no link between the detected rack and the tissues being stored therein. Hence, even if the processing information of the corresponding rack is known, this information cannot be linked with the respective tissues, i.e., the histological samples being carried by the respective carriers.
In a next step, processing is started. Therefore, the rack is provided in a corresponding processing device where—in a first step—the tissues are fixed by use of fixative solution (e.g. formalin). Then—in a second step—the tissues are dehydrated by use of dehydration reagent (e.g. ethanol). In a third step, the tissues are cleared by use of clearing reagent (e.g. isoporpanol or xylene). In a fourth step, the tissues are impregnated (or infiltrated) by use of paraffin wax.
The embedding—which is not commonly considered part of the processing and is an operation usually done outside the tissue processor—is usually done manually or, less commonly, with an automated embedder. The embedding step is required to completely fill the carrier and the impregnated tissue with paraffin wax, creating a solid block.
Afterwards, the block is cut and the slides are prepared and finally put under a microscope for corresponding analysis.
In summary, the previously described steps, in particular the tissue cutting and the tissue (carrier) preparation—are manual steps and thus they are critical for the reliability and traceability of the whole diagnosis process. In particular, in the prior art does not exist an automatic way to:                measure the size of the tissue (in particular, length, width, thickness, area and volume). In the prior art, only a thickness may be measured according to EP2009419B1;        count the tissues inside the cassette; and        give an evidence (composite picture) of how the carrier looks like at the end of preparation;        
The size of the tissue is important to define precisely the right protocol to be used to process the specimen in a tissue processor. Having the evidence of the number of tissues inside a carrier is important to be able to check the carrier during the (wax) embedding step: Sometimes it happens that one or more tissues of one carrier are lost between the tissue preparation step and wax embedding step. In the prior art does not exist a way to identify this issue. Instead knowing the number of tissues during the sample preparation allows to identify the problem at the following steps.
Furthermore, in the prior art does not exist a way to automatically collect and document that information in an effective and reliable way within a reasonable timeframe: for instance, the expected time to prepare a carrier with small biopsies is usually less than 90 seconds.
In the prior art does not exist a way to automatically track which tissues, i.e., in particular tissue carriers, were put together in a rack forming a batch at the same time when the carrier is prepared with the tissue and the rack is composed. The documentation generated from the tissue processor is usually referred to a batch. Knowing which tissues were put together in the same rack forming a batch is important to allow linking the batch documentation generated from the tissue processor to each cassette of the batch.
Otherwise, the documentation of tissue processor refers to a batch with unknown cassettes.
Moreover, the time of the process executed by the tissue processors depends on the size of the tissues to be processed. Knowing which tissues were put together in the same rack forming a batch and knowing the size of the tissues inside each cassette of the batch allows selecting the proper process for the tissue processor. In the prior art does not exist a way to recognize the right process of tissue processor based on the real size of the batch's tissues to be treated: the user of tissue processor selects a process based on guessing about size of tissues.
It is thus now an object of the present invention to provide a corresponding apparatus, system and method which overcome the aforementioned drawbacks. It is, in particular, an object of the present invention to provide a corresponding device, system and method which allows tracking of the respective tissues during the whole process, particularly with respect to number and dimension (size) of the respective tissues. This is particularly relevant since the correct tissue processing mainly depends on the type and dimension of the respective tissues.